Carries war- existing book covers

Ive started reading carries war an i'm almost finished it nothing much has happened but this book transports you back to the time of evacuation in the war really well. The story is about a brother and sister that get evacuated to wales and end up staying with a grumpy old man (Mr Evans) and his sister Lou. Overall there is quite a bit of imagery throughout the book but not a really gripping storyline. I think it could be challenging coming up with a concept for this book cover but i'm going to try out a few different things to see what works best.

 I have looked at some existing book covers and they all seem pretty similar just featuring carrie in a war setting done in an old fashioned style, although I haven't finished the whole book yet I don't quite understand why in some of the book covers war scenes are happening in the background because to my knowledge so far, she has been evacuated away from the war so i'm not sure if they really work too well. Im aware that the war theme of the story should probably feature on the cover but I think id like to make the cover look more modern as the penguin brief stated that they want a book cover that a child would pick up and ask for and I think if the cover is too mature and old fashioned looking then this wouldn't happen. I think this will be quite challenging and will take a lot of research and experimentation but will be fun to try out. Here are some of the book covers that I have came across.